Well surveying instrument



Dec. 24, 1946. w. H. EMERSON ETAL WELL SURVEYING INSTRUMEVNT Filed Jan.16, 1942 p06 .a Mw. 442.1v-v AAM/w w 2 MM wz z FP6. M.

Patented Dec. 24, 1946 WELL SURVEYIN G INSTRUMENT William H. Emerson,Long Beach, and Donald Hering, South Gate, Calif., assignors to Sperry-Sun Well Surveying Company, Philadelphia, Pa'., a corporation ofDelaware Application January 16, 1942, Serial No. 426,998

This invention relates to a well surveying instrument, and hasparticular reference to the surveying of bore holes by the so-calledgodevil method.

In the patent to Roland Ring 2,246,319, dated June 17, 1941, and in anapplication of said Roland Ring, Serial No. 379,835, filed February 20,1941, there are described an instrument and methods of operating thesame, which instrument is characterized by a slow and continuous markingaction, specifically electrolytic in character, whereby a record of theposition of the instrument within a bore hole is made only when theinstrument remains stationary for an extended period of time. For abetter understanding of the nature of the present invention, which isnot, however, limited for its application to said instrument of theabove mentioned patent and application, the operation of said instrumentmay be described as follows:

If the instrument is run into a bore hole, either within a drill stem orin an open hole by means of a wire line or cable, the movements of theinstrument incidental to its descent into the hole cause a pendulum tomove about relative to a record member, so that even though current iscontinuously flowing from the pendulum to the record member, no point ofthe record member is exposed to the current action for a suilicientlylong time to receive a denite marking. When the instrument reaches thelevel at which a record of inclination is to be made, it is brought torest and held in such position for a period upwards of about one minute,with the result that the electrolytic action is concentrated at onepoint of the record member and an easily distinguishable spot is madethereon. If it is then desired to make one or more additional records atother levels, the instrument is moved to these successive levels andpermitted to remain at them 6 Claims. (Cl. 33--205.5)

for dierent periods of time, with the result that marks differing inintensity and/or size are produced which, by Vtheir nature, can beidentied with the particular levels through a knowledge of the relativetimes during which the instrument was stationary. Following thecompletion of the member.

quires no timing means whatever. However, a

common practice in the making of records with surveying instrumentsinvolves theirbeing dropped freely through a-dri1l stein so that theycome to rest in a position adjacent the bit. During this location in aposition of rest, a record is made under the control of suitable timingmeans, and the instrument is then recovered when the bit is brought tothe surface. Generally speaking, such go-devil records are made at atime when it is necessary to bring the bit to the surface to check theprogress of the drill.

In the use of said ring instrument in go-devil fashion, the motion ofthe instrument through the drill stem prevents the making of any recordduring its fall, and a record is then vmade by holding the drill stemstationary for a suicient period of time while the vinstrument restsadjacent the bit. If the drill stem was then raised and dismantled bycontinuous work of the drilling crew, the instrument would be subject tosuiiiciently Continous agitation, with only quite limited periods ofrest, so that no record obliterating markings would be produced on therecord However, it is not usual for a derrick crew to work continuouslyin removing a drill stem from deep holesy and generally speaking,

even if some mechanical reason for delay does not occurthe workman,after raising the drill stem part way, will take a short period of restbefore proceeding further. If an instrument of the Ring type is in thedrill stem during such a period of rest, or any other period ofstationary condition of the drill stem, it will be obvious that anotherrecord will be made which might be indistinguishable from the desiredrecord unless a substantially diiierent time of rest is involved,

and even then in some rare instances. particuv larly where the hole issubstantially straight` the two records may overlap so that thesignificance of the original one is lost. It is generally not desirableto rotate the drill stem during such a period of interruption of itswithdrawal. and conseuuentlv. such rotation is Anot a practical solutionto the problem.

The present invention relates to the provision of means for terminatingthe recording action at a desired time, being particularly useful fortermination of the recording action following the completion of a singlerecord or a seriespffrecords.

This and other obiects of the invention, particularly relating todetails` will become apparent from the following description, readinconjunction with the accompanying drawing, in which:

Figures 1A. and 1B are respectively longitudicated.

bers 8 and I0. Threaded into the bottom of the lowermost tube 2 is aplug I2, on which may be secured the record member I6 by means of athreaded ring I4 provided with a flange overlapping the edge of therecord member. This record member, as described in detail in said Ringpatent and application, preferably comprises a sheet of paper containinga colored material such as a colored metallic ferrocyanide which, uponthe passage of an electrical current while it is moist will be markedwith a white spot by reason of the formation of alkali at a cathodeprovided by a metallic point I8 slidable within a pendulum mounted foruniversal pivotal movement in a bearing arrangement 22. An insulatingring 24 prevents short circuiting by preventing contact of the pendulumwith the metallic wall of the tube 2.

'I'he bearing 22 has a mounting which is insulated by means ofinsulating bushings 26 from the casing of the instrument and interposedelectrically between the bearing and a contact point is a currentlimiting or stabilizing resistor 28 of rather high resistance, forexample of the order of 100,000 ohms. Engaging the point 30 is thelowermost of one or more batteries indicated at 32 insulated by asuitable sleeve from the tube 4. These batteries are arranged in serieswith the positive pole in the uppermost position engaged with the pin 34spring pressed downwardly by a spring 36, which engages a pin 38,

the two pins 34 vand 38 and spring 36 being insulated fromcthe metallicportions of the apparatus by means of suitable insulating bushings.

Up to this point, the instrument is substantially conventional and asillustrated in said Ring application. In accordance with the Ringapplication, the equivalent of the pin 38 would be grounded to thecasing of the instrument when in operation so as to close the circuitthrough the batteries, the resistance, the pendulum and the recordmember. In the present instance, a centrifugal switching means isinterposed in the circuit.

For this purpose, the top plug 42 of the instrument which is providedwith a key way 44 engageable with a lug to hold the instrument in itsprotective casing, carries a rod 46 extending axially of the instrumentand entering a suitable hole in the coupling section l0. Secured to theplug 42 are a plurality of leaf springs 48, in this case four in number.At their lower ends, these leaf springs are connected to a collar 50,slidable on the rod 46. At their central portions, they carry weights52, the inner longitudinal surfaces of which approach quite close to therod 46. There is, however, substantial clearance provided between theleaf springs and the tube B, as in- The collar 50 is provided with anangular reduced portion 54 adapted in the position illustrated in Figure1B to hold against the pressure of a spring a finger 56 pivoted on atransverse pin 58 and provided at its lower end below. the pivot with aleaf spring 62 carrying a contact point 64 engageable with an exposedportion 40 of the pin.38. In the operation of the instrument, it islocated within a protective casing and dropped through a drill stem, therecord memberl having been moistened so as to become conductive. Duringthe period of dropping, the electrical circuit is continuously closedthrough the .po-int I8 of the pendulum, the circuit including thecontact between the point 64 and the portion 40 of the pin 38. Asindicated above, however, the motion of the pendulum during the movementthrough the drill stem prevents any substantial marking of the recordmember from occurring. After the instrument has time to reach a positionof rest adjacent the bit, resting on a suitable bridge or'merely upon ashoulder provided by a reduced passage through the bit, all motion ofthe drill stem is interrupted for a period suicient for a record to bemade. Thereupon the drill stem may be immediately rotated or partiallywithdrawn and then at some suitable time rotated to effect opening ofthe electrical circuit. This opening occurs upon rotation of the drillstem through, say, one or more revolutions by reason of the fact thatthe weights 52 are thrown centrifugally outwardly, flexing the leafsprings outwardly and thereby drawing the collar 50 upwardly along therod 46. The arrangement is such that this action will lift the collar 50olea;` of the upper end of the finger 56. As soon as this occurs, thespring 60 will force the nger outwardly to the dotted line positionindicated in Figure 1B, breaking the electrical contact. If, then, therotation ceases, the inward ilexure of the springs 48 will tend to movethe collar 50 downwardly, but this downward movement is arrested by itsengagement with the upper end of the nger 56. A's a result, the circuitis not remade. Accordingly, if, thereafter, the drill stem is stationaryover any extended period of time, the record member will not be further'marked. In fact, if for some reason it is not necessary to read therecord immediately, the instrument may be set aside even in an uprightposition, and no record will be made. Normally, the instrument is soarranged that interruption of the circuit occurs upon inverting it byreason of the fact that the pin I8 will drop within the pendulum out ofcontact with the record disc.

It will be evident that the circuit may be remade for a subsequentoperation merely by the operators pressing inwardly the lower portion ofthe iinger 56 through the opening 66 in the coupling lll.V Whenthis isdone, the upper end of the nger will clear the collar 50 and permit itto move into the position illustrated, wherein it will retain the finger56 in circuit closing position.

The arrangement illustrated is designed to prevent accidental opening ofthe circuit except upon rotation of the instrument through the parted tothe instrument would tend to cause all of the weights 52 to move in thesame direction, which would mean that one or more oi' them would have tomove in a direction toward the rod 46. As mentioned above, the clearancefor movement in this direction is small, and consequently an extent ofmovement sufficient to aaiaare raise the collar Eil to clear the nger Sis impossible. The setting up of vibrations which might eiect movementof the collar 50 is also impossible for this same reason, i. e., sincethe weights 52 cannot move to any extent inwardly, it is substantiallyimpossible that amplitudes of vibration could be set up which, bycorresponding in phase, would raise the collar. Inertial movementslengthwise of the rod 46 can also be made to have substantially noeffect merely by pro.

viding a very slight initial inward bowing of the springs a8. The systemis, in fact, extremely stable against any motions except rotary ones,and since, by a suitable proportioning of the masses of the weights aand the tension of the springs de, a centrifugal outward movement of thesprings suiiicient to move the collar 50 to open the switch may beprevented except for a predetermined speed of rotation, incidental slowrotation of the instrument occurring during its drop through the drillstem, or slight angular movements of the drill stem occurring before aswitch opening rotation will-be completely ineffective to break thecircuit. A

While the centrifugally controlled switch has been describedspecifically in connection with the Ring type instrumentfit will beevident that it is applicable in the case of many other surveyinginstruments involving an electrical circuit ar.- ranged to effect somecontrol. It may also be noted that the control may be effected throughclosure rather than opening of a circuit upon centrifugal action. Infact, this Ring type instrument is a good example of such possibilitysince the switch might well be arranged in a circuit shunting the pointof engagement of the pin I8 with the record member. If closed to shortcircuit this contact, the 4recording action would cease. If the switchwas arranged in series with a high resistance such as 28, this shortcircuiting action would not resultin any current drain on the batteriesof a damaging character. It will be evident that various changes may bemade in the specic embodiment of the invention, and particularly in thearrangement of the centrifugal device to render it proof againstresponse to accidental vibration by the use of damping means of knowntype.

What we claim and desire to protect by Letters Patent is:

1. A well surveying .instrument comprising a casing adapted to enter abore hole, means for supporting a record member within said casing,means, comprising an electrical circuit, for effecting marking of saidrecord member in accordance with the position of said casing, and meansfor controlling flow of current in said circuit, said ance with theposition of said casing, and means for controlling ow of current in saidcircuit, said means comprising switching elements and devices responsiveto rotation of said casing to effect' relative movements of `saidswitching elements.

3. A well surveying instrument comprising .a

lcasing adapted to enter a bore hole, means for supporting a recordmember within said casing, means, comprising an electrical circuit, foreffecting marking of said record member in accordance with the positionof said casing, and means for controlling ow of current in said circuit,said means comprising devices responsive to rotation of said casing toeiect said control, said devices including a plurality of weightedspring elements secured to each other at their upper and lower ends andarranged to detiect upon the application of centrifugal forces.

4. A well surveying instrument comprising a casing adapted to enter abore hole, means for supporting a record member within said casing,means, comprising an electrical circuit, for effecting marking of saidrecord member in accordance with the position of said casing, and meansfor controlling ow of current in said circuit. said means comprisingdevices responsive to rotation of said casing to effect said control,said devices including a plurality of weighted spring elements securedto each other at one set of ends thereof, a collar to which saidelements are secured at their opposite ends, and means for guiding saidcollar for movement in the direction of the axis of the casing butpreventing movement of the collar transversely to said axis, said springelements being arranged to deect upon the application of centrifugalforces.

5. A well surveying instrument comprising a casing adapted to enter abore hole, means for supporting la record member within said casing,means, comprising an electrical circuit, for effecting marking of saidrecord member in accordance with the position of said casing, and meansfor controllingkow of current in said circuit, said means comprising aspring urged switch element, and means normally restraining said elementfrom movement under the spring action but arranged to trip the switchelement in response to rotation of said casing.

6. A well surveying instrument comprising a casing adapted to enter abore hole, means fory supporting a record member within said casing,means responsive to the position of the instrument for effecting slowmarking of said record member, said responsive means being subject todisturbance by movements of the instrument and being active withoutinterruption for any substantial time during an extended period ofloca-v tion of the instrument within a bore hole to eiect such marking,the rate at which appreciable marking of said record member occurs beingso low that during movements of the instrument during said extendedperiod no appreciable marking occurs, and centrifugally controlled meansfor interrupting lsaid marking so that, following a marking operationduring a stationary period of said instrument, marking during asubsequent stationary period may be prevented by rotation of theinstrument. y WILLIAM H. EMERSON.

DONALD HERING.

